The purpose of this study is to evaluate the clinical utility of CA-125 as a diagnostic test for endometriosis by drawing serum CA-125 levels in the follicular, luteal, and menstrual phases of the menstrual cycle in patients undergoing laparoscopy. Student's t-test and ANOVA, where applicable, will be utilized to compare endometriosis vs. non-endometriosis patients as well as the stages of endometriosis. Uses only the CDMAS facility.